State of the art electronic systems typically include a plurality of functional elements in very compact modular subsystems. In such subsystems the functional elements are connected to common supply busses. Because of the compactness of the subsystems the supply busses may have not insignificant impedances. Often the current drawn from the supply busses by the functional elements is signal dependent, that is the current drawn by particular elements is not constant. Variations in the current drawn by the functional elements, in conjunction with the impedance of the supply busses will cause local time varying supply potentials being applied to respective functional elements. Such supply potential variations may adversely affect the transfer functions of particular elements.
Local supply potential variations may be precluded by, for example, including bypass capacitors at each functional element, however this solution tends to undesirably complicate the placement of functional elements in a highly compact system and/or undesirably enlarge the subsystem. This is particularly true where the subsystem is contained in an integrated circuit.
A solution to supply potential variation in an integrated circuit environment is set forth in U.S. Pat. No. 4,327,332 wherein a plurality of amplifiers are coupled to common supply busses. To preclude localized supply potential variations undesirably affecting the response of the respective amplifiers, each of the amplifiers is coupled to the supply bus via respective voltage regulator circuitry. The respective voltage regulators however tend to substantially increase overall circuit complexity and to be sensitive to temperature changes, etc.